In automation technology, especially in process automation technology, field devices are often applied, which serve for registering and/or influencing process variables. Serving for registering process variables are sensors, which are integrated, for example, in fill level measuring devices, flow measuring devices, pressure- and temperature measuring devices, pH-redox potential measuring devices, conductivity measuring devices, etc., for registering the corresponding process variables, fill level, flow, pressure, temperature, pH-value, redox potential, or conductivity register. Serving for influencing process variables are actuators, such as, for example, valves or pumps, via which the flow of a medium in a pipeline section, or the fill level in a container, can be changed. Referred to as field devices are, in principle, all devices, which are applied near to the process and which deliver, or process, process relevant information. In connection with the invention, the terminology, field devices, thus refers also to remote I/Os, radio adapters, or generally electronic components, which are arranged at the field level. A large number of such field devices are produced and sold by the firm, Endress+Hauser.
Independently of the particular field device type, field devices are, as a rule, connected via a bus system with a superordinated unit, for example, a process control system. This serves, on the one hand, for reporting the registered process variables. Due to its robustness, used as signal type for this is a standard signal, as a rule, the 4-20 mA signal. Moreover, also additional information, for example, concerning the operating state of the field device, can be communicated to the superordinated unit. For this, supplementally, a digital signal is modulated onto the 4-20 mA signal. Conventional protocols in the field of process automation are, for instance, “PROFIBUS”, “HART” or “Wireless HART”.
Since, independently of the particular field device type, the same communication protocol to the superordinated unit can be used, it is possible for the manufacturer to use the same communication module in different field device types. In this way, there results the opportunity for modular manufacturing in the case of a large number of different field device types. For this, it is, however, necessary that the circuit board or assembly, on which the communication module is located, be adapatable to the different field device types.
Known from the publication WO 2015/147993 is a circuit board plug connection, which can be used in a field device. Shown there is a plug with a plurality of connection pins, wherein a connector of an electrical wire can be screwed, in each case, onto one pin. Because of the pins, it is easy to plug the plug into corresponding sockets on the circuit board. However, in the case of this type of plug connection, a protection against slipping out of the plug is not provided.